b-Substances transported by facilitated diffusion 1. move passively via help fro

Question

b-Substances transported by facilitated diffusion
1. move passively via help from carrier proteins from an area of greater concentration to one of lower concentration.
2. are limited to solvents.
3. must have movements coupled to those of other substances.
4. may flow to a region of higher concentration by expenditure of energy.
5. are restricted to only one direction through the membrane.

c-By a mechanism called cotransport,
1. sugar moves inward down its concentration gradient while sodium moves inward up its concentration gradient.
2. sodium moves outward against its concentration gradient while sugar moves inward down its concentration gradient.
3. sugar and sodium both move inward down their concentration gradients.
4. sodium moves inward down its concentration gradient while sugar moves inward up its concentration gradient.
5. both sodium and sugar move outward up their concentration gradients.

a-Lipoproteins like LDL and HDL transport lipids and proteins through the blood stream. Receptors on cells can bind to the lipoproteins and remove them from the blood, using the lipids for energy and to produce membranes. Which of the following mechanisms would be used to move a lipoprotein into a cell?
1. active transport
2. facilitated diffusion
3. diffusion
4. endocytosis
5. exocytosis

Explanation / Answer

a. 4: receptor mediated endocytosis
b 1: carrier proteins act as channels for transport
c 4: One molecule moves down its concentration gradient giving energy for the other molecule to move up its concentration gradient.

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.